•S0\I9   OUOliHO 


129G  Issued  August  30,  1910. 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 


FARMERS'   BULLETIN  413. 


THE  CARE  OF  MILK  AND  ITS  USE 
;■  IN  THE  HOME. 


GEORGE  M.  WHITAKER, 

hi  Charge  of  JMarket  Milk  Investigations^  Dairy  Division, 
Bureau  of  Animal  Industry, 

L.  A.  ROGERS, 

Bacteriologist  in  Charge  of  Research  Laboratories,  Dairy 
Division,  Bureau  of  Animal  Industry, 


CAROLINE  L.  HUNT, 
Expert  in  Nutrition,  Office  of  Experiih 


WASHINGTON: 

GOVERNMENT     PRINTING     OFFICE. 
1910. 


/ 


V 


LETTER  01-  TRANSMITTAL 


U.  S.  Depaktment  of  Agricut.ture, 

Washington,  D.  C,  May  IS,  1910. 
Sir:  We  have  the  honor  to  transmit  herewith,  and  to  recommend 
for  piibUcation  as  a  Farmers'  Bulletin,  three  articles,  namely:  "The 
Care  of  Milk  in  the  Home,"  by  George  M.  "W^iitakcr,  in  charge  of 
market  milk  investigations,  Dairy  Division,  Bureau  of  Animal  Indus- 
tr}^;  "The  Home  Pasteurization  of  Milk,"  by  L.  A.  Rogers,  bacteri- 
ologist in  charge  of  the  research  laboratories  of  the  Dairy  Division, 
Bureau  of  Animal  Industry;  and  "Food  Value  of  Milk,"  by  Caroline 
L.  Hunt,  expert  in  nutrition,  Office  of  Experiment  Stations. 

The  material  which  has  to  do  with  the  food  values  of  milk  was 
prepared  under  the  supervision  of  C.  F.  Langworthy,  expert  in 
charge  of  nutrition  investigations,  Office  of  Experiment  Stations. 

The  present  bulletin  is  similar  in  scope  and  purpose  to  the  popular 
publications  which  the  Department  has  issued  in  the  past,  and  sum- 
marizes available  information  on  a  subject  which  is  of  great  impor- 
tance to  most  American  families. 

Respectfully,  A.  D.  Melvin, 

Chief  Bureau  of  Animal  Industry. 
A.  C.  True, 
Director  Office  of  Experiment  Stations. 
Hon.  James  Wilson, 

Secretary  of  Agriculture. 

413 
2 


CONTENTS, 


Pa?e. 

The  Care  of  Milk  in  the  Home,  by  George  M.  ^Yhitaker 5 

Introduction '^ 

Receiving  the  milk " 

Handling  and  keeping  milk ^ 

The  refiigerator ^ 

Cleaning  empty  bottles  and  utensils 7 

Contagious  disease ^ 

Pasteurization ^ 

The  Home  Pasteurization  of  Milk,  by  L.  A.  Rogers 9 

Introduction " 

Method  of  pasteurization 9 

Food  Value  of  Milk,  by  Caroline  L.  Hunt H 

Introduction 11 

The  composition  of  milk 1^ 

Economical  use  of  milk 14 

Food  value  of  skim  milk 1^ 

Milk  soups 1 ' 

Milk  chowder l' 

Milk  gravies 1' 

Cottage  cheese 1^ 

Sweet  curds ^^ 

Milk  desserts 1^ 

Buttermilk 1^ 

Summary "" 

413  3 


284450 


THE  CARE  OF  MILK  AND  ITS  USE  IN  THE 

HOME. 


THE  CAEE  OF  MILK  IN  THE  HOME. 

By  George  M.  Whitaker, 
In  Charge  of  Market  Milk  Investigations,  Dairy  Division,  Bureau  of  Animal  Industry. 


INTRODUCTION. 

If  the  milk  producer  and  the  milk  dealer  have  done  their  duty  there 
is  daily  left  at  the  consumer's  door  a  bottle  of  clean,  cold,  unadul- 
terated milk.  By  improper  treatment  in  the  home  the  milk  may 
then  become  unfit  for  food,  especially  for  babies.  This  bad  treat- 
ment consists  (1)  in  placing  it  in  unclean  vessels;  (2)  in  exposing  it 
unnecessarily  to  the  air;  (3)  in  failing  to  keep  it  cool  up  to  the  time  of 
using  it;  and  (4)  in  exposing  it  to  flies. 

Milk  absorbs  impurities — collects  bacteria — whenever  it  is  exposed 
to  the  air  or  placed  in  unclean  vessels.  Some  of  these  may  be  the 
bacteria  of  certain  contagious  diseases;  others  may  cause  digestive 
troubles  which  in  the  case  of  babies  may  prove  fatal.  Much  of  the 
cholera  infantum  and  summerbowel  troubles  of  infants  is  due  to  impure 
milk.  The  amount  of  the  contamination  depends  largely  on  the 
condition  of  the  utensils  and  the  air  with  which  the  milk  comes  in 
contact;  the  air  of  even  a  so-called  clean  room  contains  many  impu- 
rities. The  science  of  bacteriology  is  raising  the  standard  of  clean- 
liness of  utensils.  Bacteria  which  get  into  the  milk  from  the  air  or 
from  the  vessels  multiply  rapidly  so  long  as  the  milk  remains  warm; 
that  is,  at  50°  F.  or  above.  At  lower  temperatures  the  bacteria  either 
are  dormant  or  increase  slowl}^.  Cleanliness  and  cold  are  imperative 
if  one  would  have  good  milk,  although  if  it  is  consumed  so  Cfuickly 
after  production  that  the  bacteria  in  it  do  not  have  time  to  increase 
much — say  within  two  or  three  hours — the  importance  of  cold  is 
lessened.  Milk  from  the  grocery  store  or  bakery  which  is  kept  in  a 
can,  open  much  of  the  time,  possibly  without  refrigeration,  is  danger- 
ous and  should  be  avoided. 

The  suggestions  given  here  regarding  milk  apply  also  to  cream. 
413  5 


.6  CAEE    OF    MTLK   AND    ITS   USE    IN    THE    HOME. 

RECEIVING  THE  MILK. 

The  host  way  of  l)uyinn:  milk  is  in  bottles.  Dipping  milk  from 
largo  cans  anil  pouring  it  into  customers'  receptacles  on  the  street, 
with  all  the  incident  exposure  to  dusty  air  not  always  the  cleanest, 
is  a  bad  practice.  Drawing  milk  from  the  faucet  of  a  retailer's  can 
is  almost  as  bad  as  dipping,  because,  although  the  milk  may  be 
exposed  to  the  street  air  a  little  less  than  by  the  dipping  process,  it 
is  not  kept  thoroughly  mixed,  and  some  consumers  will  receive  less 
than  their  proportion  of  cream.  If  situated  so  that  it  is  impossible 
to  get  bottled  milk,  do  not  set  out  overnight  an  uncovered  vessel  to 
collect  thousands  of  bacteria  from  street  dust  before  milk  is  put  into 
it.  Have  the  milk  delivered  personally  to  some  member  of  the  family 
if  possible;  if  not,  set  out  a  bowl  covered  with  a  plate,  or  better  still, 
use  a  glass  preserving  jar  in  which  nothing  but  milk  is  put.  In  the 
latter  case  use  a  jar  with  a  glass  top,  but  omit  the  rubber  band. 
Paper  tickets  are  often  more  or  less  soiled;  hence  if  they  are  used  do 
not  put  them  in  the  can,  bowl,  or  jar.  For  the  same  reason  money 
should  not  be  put  in  the  can. 

Take  the  milk  into  the  house  as  soon  as  possible  after  tlelivery, 
particularly  in  hot  weather.  Never  allow  the  sun  to  shine  for  any 
length  of  time  on  the  milk.  Sometimes  milk  delivered  as  early  as  4 
a.  m.  remains  out  of  doors  until  9  or  10  o'clock.  This  is  wrong.  If 
it  is  inconvenient  to  receive  the  milk  soon  after  it  is  delivered,  indicate 
to  the  driver  a  sheltered  place,  or  })rovide  a  covered  box  in  which  the 
milk  bottle  or  can  may  be  left. 

HANDLING  AND  KEEPING  MILK. 

On  receiving  the  milk  put  it  in  the  refrigerator  at  once  and  allow 
it  to  remain  there  when  not  using  from  it.  Except  in  cold  weather 
milk  can  not  be  properly  kept  without  ice.  Unless  the  milk  bottle  is 
in  actual  contact  with  the  ice  it  will  be  colder  at  the  bottom  of  the 
refrigerator  than  in  the  ice  compartment,  as  the  cold  air  settles 
rapidly. 

Keej)  milk  in  the  original  bottle  till  needed  for  immediate  con- 
sumption; do  not  pour  it  into  a  bowl  or  pitcher  for  storage.  Care- 
fully wipe  or  rinse  the  bottle,  especially  the  mouth,  before  pouring  any 
milk  from  it,  so  that  dust  or  dirt  which  may  have  gathered  thereon 
or  on  the  cap  will  not  get  into  the  milk.  Do  not  pour  back  into  the 
bottle  milk  which  has  been  exposed  to  the  air  by  being  placed  in  other 
vessels.  Keep  the  bottle  covered  with  a  paper  cap  as  long  as  milk 
is  in  it  and  wdien  not  actually  pouring  from  it.  If  the  paper  cap  has 
been  punctured,  cover  the  bottle  with  an  inverted  tumbler. 

413 


CAEE   OF   MILK   AND   ITS   USE   IN    THE   HOME.  7 

Milk  deteriorates  by  exposure  to  tlie  air  of  pantry,  kitchen,  or 
nursery.  Do  not  expose  uncovered  milk  in  a  refrigerator  containing 
food  of  any  kind,  not  to  mention  strong-smelling  foods  like  fish,  cab- 
bage, or  onions.  An  excellent  way  of  serving  milk  on  the  table,  from 
the  sanitary  standpoint,  is  in  the  original  bottle;  at  all  events  pour 
out  only  what  will  be  consumed  at  one  meal. 

When  milk  is  received  in  a  bowl  or  pitcher  instead  of  in  a  bottle, 
observe  the  spirit  of  the  foregoing  remarks :  Keep  the  vessel  covered ; 
expose  uncovered  milk  to  the  air  of  any  room  as  little  as  possible ; 
do  not  expose  it  at  all  in  a  refrigerator. 

Remember  that  exposure  of  milk  to  the  open  air  invites  contami- 
nation not  only  from  odors  and  bacteria-laden  dust,  but  also  from 
flies.  These  scavengers  may  conveys  germs  of  typhoid  fever  or  other 
contagious  diseases  from  the  sick  room  or  from  excreta  to  the  milk. 

Records  show  typhoid  epidemics  from  such  a  cause,  and  100,000 
fecal  bacteria  have  been  found  on  a  single  fly.  Flies  also  frequently 
convey  to  milk  large  numbers  of  the  bacteria  that  cause  intestinal 
disorders  in  infants;  an  examination  of  414  flies  showed  an  average 
of  1,250,000  bacteria  per  fly. 

THE  REFRIGERATOR. 

Keep  the  refrigerator  clean  and  sweet.  Personally  mspect  it  at 
least  once  a  week.  'See  that  the  outlet  for  water  formed  by  the  melt- 
ing ice  is  kept  open  and  that  the  space  under  the  ice  rack  is  clean. 
The  place  where  food  is  kept  should  be  scalded  every  week;  a  single 
drop  of  spilled  milk  or  a  small  particle  of  other  neglected  food  will 
contaminate  a  refrigerator  in  a  few  days. 

CLEANING  EMPTY  BOTTLES  AND  UTENSILS. 

As  soon  as  a  mflk  bottle  is  empty  rmse  it  m  lukewarm  water  until 
it  appears  clear,  then  set  it  bottom  up  to  drain.  Do  not  use  it  for 
any  other  purpose  than  for  milk.  There  is  no  objection  to  the  con- 
sumer's washing  and  scalding  the  milk  bottle,  but  this  is  unnecessary, 
as  the  dealer  will  wash  it  again  when  it  reaches  his  plant.  He  can 
not,  however,  do  this  properly  if  he  receives  the  bottle  in  a  filthy 
condition,  and  if  you  return  such  a  bottle  your  negligence  may  result 
in  the  subsequent  deliver}''  of  contaminated  milk  to  some  consumer, 
possibly  yourself. 

All  utensils  with  which  milk  comes  in  contact  should  be  rinsed, 
washed,  and  scalded  every  time  they  are  used.  Use  fresh  water;  do 
not  wash  them  in  dishwater  which  has  been  used  for  washing  other 
utensils  or  wipe  them  with  an  ordinary  dish  towel — it  is  better  to 
boil  in  clean  water  and  set  them  away  unwiped. 

413 


UNIVERSITY 

CF 


8  CARE   OF   MILK   AND   ITS   USE   IN    THE   HOME. 

When  a  baby  is  bottle-fed,  every  time  the  feeding  bottle  and  nipple 
are  used  they  should  be  rinsed  in  lukewarm  water,  washed  in  hot  water, 
to  which  a  small  amount  of  washing  soda  has  been  added,  and  then 
scalded.  Never  use  a  rubber  tube  between  bottle  and  nipple,  or  a 
bottle  with  corners, 

CONTAGIOUS  DISEASE. 

If  a  case  of  typhoid  fever,  scarlet  fever,  diphtheria,  or  other  con- 
tagious disease  breaks  out  in  the  family,  do  not  return  any  bottles 
to  the  milkman  except  with  the  knowledge  of  the  attending  physi- 
cian and  under  conditions  i)rescribed  b}^  him. 

PA  STEURIZ  ATION. 

While  efficient  pasteurization  destroys  disease  germs  and  affords 
a  safeguard  against  certain  dangers,  it  should  not  be  regarded  as  an 
insurance  against  future  contamination  of  milk,  and  the  foregoing 
suggestions  should  be  observed  in  the  case  of  i)asteurized  milk  as 
well  as  with  ordinary  milk.  Do  not  keep  milk  over  twenty-four 
hours,  even  if  it  seems  to  be  sweet,  as  milk  may  become  unfit  for 
human  food  before  it  sours. 

413 


THE  HOME  PASTEURIZATION  OF  MILK. 

By  L.  A.  Rogers. 
Bacteriologist,  Dairy  Division,  Bureau  of  Animal  Industry. 


INTBODUCTION. 

Milk  delivered  in  tlie  cities  in  the  summer  months  frequently  con- 
tains bacteria  in  such  large  numbers  that  it  is  not  a  safe  food  for 
children,  especially  for  infants  whose  food  consists  entirely  of  milk. 
In  many  cities  a  special  milk  can  be  secured,  but  this  is  sometimes 
diflicult  and  always  involves  additional  expense. 

Under  such  circumstances  it  is  advisable  to  pasteurize  all  milk  con- 
sumed by  small  children.  The  pasteurization  should  be  done  in  such 
a  way  that  disease-producing  bacteria  as  well  as  those  likely  to  pro- 
duce intestinal  disturbances  are  destroyed  without  at  the  sam.e  time 
injuring  the  flavor  or  the  nutritive  value  of  the  milk.  This  may  be 
accomplished  in  the  home  by  the  use  of  a  simple  improvised  outfit. 

METHOD  OF  PASTEUHIZATION. 

Milk  is  most  conveniently  pasteurized  in  the  bottles  in  which  it  is 
delivered.  To  do  this  use  a  small  pail  with  a  perforated  false  bottom.. 
An  inverted  pie  tin  with  a  few  holes  punched  in  it  will  answer  this 
purpose.  This  will  raise  the  bottles  from  the  bottom  of  the  pail,  thus 
allowing  a  free  circulation  of  water  and  preventing  bumping  of  the 
bottles.  Punch  a  hole  through  the  cap  of  one  of  the  bottles  and 
insert  a  thermometer.  The  ordinary  floating  type  of  thermometer  is 
likely  to  be  inaccurate,  and  if  possible  a  good  thermometer  with  the 
scale  etched  on  the  glass  should  be  used.  Set  the  bottles  of  milk  in 
the  pail  and  fill  the  pail  with  water  nearly  to  the  level  of  the  milk. 
Put  the  pail  on  the  stove  or  over  a  gas  flame  and  heat  it  until  the 
thermometer  in  the  milk  shows  not  less  than  150°  nor  more  than 
155°  F.  The  bottles  should  then  be  removed  from  the  water  and 
allowed  to  stand  from  twenty  to  thirty  minutes.  The  temperature 
will  fall  slowly,  but  may  be  held  more  uniformly  by  covering  the 
bottles  with  a  towel.  The  punctured  cap  should  be  replaced  with  a 
new  one,  or  the  bottle  should  be  covered  with  an  inverted  cup. 

52054°— Bull.  413—10 2  9 


10  CARE   OF   MILK   AND   ITS   USE   IN   THE   HOME. 

After  the  milk  has  been  held  as  directed  it  should  be  cooled  as 
quickly  and  as  much  as  possible  by  setting  in  water.  To  avoid 
danger  of  breaking  the  bottle  by  too  sudden  change  of  temperature, 
this  water  should  be  warm  at  first.  Replace  the  warm  water  slowly 
with  cold  water.  After  cooling,  milk  should  in  all  cases  be  hold  at 
the  lowest  available  temperatm-e. 

This  method  may  be  employed  to  retard  the  souring  of  milk  or 
cream  for  ordinary  uses.  It  should  be  remembered,  however,  that 
pasteurization  does  not  destroy  all  bacteria  in  milk,  and  after  pas- 
teurization it  should  be  kept  cold  and  in  a  cleanl}'"  manner  and  used 
as  soon  as  possible.  Cream  does  not  rise  as  rapidly  or  separate  as 
completely  in  pasteurized  milk  as  in  raw  milk. 

413 


FOOD  VALUE   OF  MILK. 

By  Caroline  L.  Hunt, 

Expert  in  Xutrition,  Office  of  Experiment  Stations. 


INTRODUCTION. 

It  is  a  commonplace  saying  that  milk,  or  to  be  more  specific,  cow's 
milk,  is  a  perfect  food.  This  may  be  taken  to  mean  that  it  contains, 
first,  materials  which  children  need  for  growth;  second,  materials  which 
young  and  old  alike  need  for  the  repair  of  their  bodily  machiner}?^; 
and,  third,  materials  which  both  need  for  fuel,  i.  e.,  to  provide  them 
with  heat  and  with  the  energy  necessary  for  work.  It  should  not 
be  understood,  however,  to  mean  that  it  has  these  ingredients  in  such 
proportions  that  it  can  serve  satisfactorily  as  an  exclusive  food  for  a 
grown  person  or  even  for  a  child.  Though  it  is  the  best  substitute  for 
mother's  milk,  it  must  be  "modified"  more  or  less  before  it  can  be 
used  even  for  infant  feeding  with  good  results. 

It  is  likewise  a  commonplace  saying  that  milk  is  a  cheap  as  well  as  a 
nutritious  food.  Just  at  present  with  prices  of  all  kinds  of  foods 
rapidly  changing  it  is  not  so  easy  as  it  once  was  to  make  the  com- 
parisons that  are  necessary  to  show  which  particular  foods  are 
really  cheap,  but  while  the  prices  of  food  materials  vary  the  compo- 
sition of  most  of  them  remains  unchanged,  and  it  is  always  possible 
to  compare  their  nutritive  values.  A  quart  of  milk  supplies  practi- 
cally as  much  of  both  protein  and  energy  as  three-c^uarters  of  a 
pound  of  beef  of  average  composition  or  eight  average  eggs,  and  can 
generally  be  bought  for  less  money.  In  case  milk  is  8  cents  a  cjuart, 
beef  20  cents  a  pound,  and  eggs  24  cents  a  dozen,  10  cents  spent  for 
milk  will  buy  a  little  more  protein  and  much  more  energy  than  10 
cents  spent  for  beef  or  10  cents  spent  for  eggs.  Thus,  while  other 
animal  foods  than  milk  (meat,  eggs,  and  cheese)  are  desirable  to  give 
variety  to  the  diet  it  may  be  assumed  that  milk  may  be  used  as 
an  economical  substitute  for  any  one  of  them. 

Of  the  vegetable  foods,  many  (flour,  for  example)  are  found  to  be 
much  cheaper  than  milk  when  both  price  and  nutritive  value  are 
taken  into  consideration,  and  as  a  matter  of  fact  they  always  form  the 
greater  part  of  the  bulk  of  human  food;  but  of  the  animal  foods 
which  are  usually  combined  with  the  vegetable  foods,  milk  is  one  of 
the  cheapest. 

413  11 


12  CAKE   OF   MILK   AND   ITS   USE   IN   THE   HOME. 

In  spite  of  the  fact  that  milk  is  recognized  as  a  nutritious  and  a 
clieap  food,  there  seems  to  be  a  general  tendency  to  think  of  it  not 
as  a  possible  substitute  for  other  more  expensive  foods,  but  rather 
as  an  addition  to  the  bill  of  fare.  To  illustrate,  milk  is  frequently 
used  as  a  beverage  without  the  reduction  of  the  amount  of  meat  or 
other  proteid  foods  served.  From  the  point  of  view  of  the  need  of 
the  body  this  may  be  considered  extravagant  and  the  serving  of  a 
glass  of  milk  or  of  a  bowlful  of  soup  or  of  such  desserts  as  custards 
and  baked  milk,  or  the  use  of  generous  quantities  of  milk  or  white 
sauce  on  vegetables  offers  an  opportunity  to  cut  down  the  allowance  of 
meats  and  eggs. 

THE  COMPOSITION  OF  MILK. 

The  tendency  to  think  of  milk  as  a  beverage  rather  than  as  an 
important  source  of  food  comes  partly,  no  doubt,  from  the  fact  that 
it  is  a  liquid  rather  than  a  solid  and  that  most  liquid  foods,  such  as 
clear  soup,  coffee,  and  tea,  contain  very  little  that  feeds  the  body. 
It  is  natural,  therefore,  to  associate  milk  with  these  rather  than  with 
the  really  nourishing  food  materials.  In  order  to  overcome  this 
tendency  it  is  well  to  study  the  sohd  products  of  milk  as  they  are 
obtained  by  various  processes  familiar  in  the  dairy  and  in  the  kitchen 
as  well  as  in  the  laboratory.  Before  doing  this  it  may  be  helpful  to 
get  an  idea  of  the  classes  into  which  the  solids  contained  in  milk  are 
divided.  These  are:  (1)  Proteids,  (2)  fats,  (3)  sugar,  and  (4)  mineral 
matter.  The  fat  and  sugar  serve  as  fuel,  and  the  mineral  matter  is 
cliiefly  valuable  for  the  making  of  bones  and  teeth  and  other  physio- 
logical purposes.  The  proteids  serve  as  fuel  hke  the  fats  and  sugar, 
but  they  are  used  also  to  make  and  to  repair  the  muscular  tissues  of 
the  body.  This  double  usefulness  indicates  why  proteids  are  so 
often  referred  to  as  the  most  important  part  of  milk. 

Fat  constitutes  about  4  per  cent  of  the  weight  of  milk.  All  are 
familiar  with  the  common  process  of  butter  maldng  by  which  the 
greater  part  of  the  fat  is  separated  from  the  other  ingredients.  The 
liquid  which  remains  and  which  is  called  buttermilk  contains  the  rest 
of  the  nutrients  of  the  milk  except  the  small  portions  wliich  cling  to 
the  fat.  On  examining  buttermilk  after  it  has  become  a  little  sour,  it 
may  be  seen  that  it  contains  a  white  solid  which  in  the  process  of 
churning  has  been  divided  into  very  small  particles.  This  solid  is 
casein,  the  chief  proteid  of  the  milk.  It  constitutes  3.3  per  cent,  or 
about  one-thirtieth,  of  the  weight  of  the  milk. 

The  familiar  process  of  the  souring  of  milk  also  helps  to  an  under- 
standing of  its  composition.  When  this  takes  place  the  casein  and 
most  of  the  fat  separate  from  the  whey  and  form  what  is  known  as 
the  curd.     When,  however,   the  attempt  is  made   to  separate  the 

413 


CARE   OF   MILK   AND   ITS   USE   IN    THE   HOME.  13 

curd  completely  for  the  purpose  of  making  cottage  cheese,  much  of 
the  fat  is  usually  carried  off  with  the  whey.  This  is  particularly 
true  if  the  curd  is  strained  while  warm.  It  may  therefore  be  in 
place  here  to  suggest  that  after  sour  milk  has  been  scalded  for  the 
purpose  of  making  cottage  cheese  it  is  well  to  chill  it  thoroughly 
before  straining.  Through  very  common  processes,  those  of  butter 
and  cheese  making,  one  may  become  familiar  with  the  solid  known 
as  casein  and  with  the  fat  of  milk.  But  the  clear  whey  which  may  be 
separated  from  the  curd  also  has  important  solids  in  it  and  with  these 
one  seldom  has  a  chance  to  become  acquainted.  The  following 
simple  experiment  may  be  carried  out  with  the  ordinary  dishes  in 
use  in  the  kitchen: 

Separate  a  portion  of  whey  from  the  curd  of  sour  milk,  and,  if 
necessary  to  make  it  perfectly  clear,  strain  through  a  piece  of  fine 
cloth  \vithout  previously  heating.  Examine  to  see  that  there  are  no 
solid  particles  in  it.  Divide  into  two  parts.  Heat  one  part  to  the 
boiling  point,  and  when  cool  pour  into  a  glass,  examine,  and  compare 
with  the  unheated  portion.  The  part  that  has  been  heated  will  be 
seen  to  be  full  of  small  particles  of  a  white  solid  which  soon  sink  to 
the  bottom  of  the  liciuid.  This  is  albumen,  a  substance  alwa^^s  pres- 
ent in  cow's  milk,  though  in  very  much  smaller  amount  than  the 
casein.  It  resembles  the  albumen  of  the  white  of  an  egg.  It  differs 
from  the  casein  in  not  curding  when  the  milk  soure  and  in  remaining 
in  solution  in  tlie  whey.  Furthermore,  it  does  not  form  curd  in  the 
stomach.  This  experiment  is  particularly  important  to  those  who 
wish  to  understand  milk  in  its  relation  to  the  feeding  of  babies.  The 
proteid  which  by  the  process  of  heating  is  shown  to  be  present  in 
the  whey  is  the  chief  proteid  of  human  milk,  while  in  cows'  mUk,  as 
has  been  said,  it  is  found  in  very  much  smaller  amount  than  the 
curding  proteid.  Cows'  milk,  therefore,  can  never  be  a  perfect  equiv- 
alent for  human  milk  in  im'ant  feeding,  even  if  diluted  and  modified, 
though  it  may  be  the  best  available  substitute  for  it.  It  is  easy  to 
understand  that  a  bab}^  m^^y  be  able  to  digest  a  proteid  which 
remains  dissolved  in  the  whey  more  easily  than  one  which  curds  soon 
after  reaching  the  stomach. 

To  continue  the  experiment  with  milk,  strain  the  whey  which  has 
been  heated  and  again  get  a  clear  liquid.  Pour  this  into  a  double 
boiler  over  water  and  heat  until  it  is  dry.  There  will  be  left  a  solid 
sugary  mass.  Place  some  of  this  in  an  old  spoon  or  on  a  piece  of  tin 
or  sheet  iron  and  burn.  Notice  the  characteristic  odor  of  charred 
sugar.  Milk  contains  5  per  cent  of  sugar.  This  sugar  is  not  exactly 
like  the  sugar  used  on  the  table.  It  is  much  less  sweet  and  physi- 
ologists and  chemists  find  that  it  acts  differently  from  ordinary  sugar 
during  the  process  of  digestion.     For  this  reason  the  sugar  used  in 

413 


14  CABE   OF   MILK   AND   ITS   USE   IN   THE   HOME. 

preparing;  a  baby's  food  should  never  be  pjranulated  sugar,  but  milk 
sugar,  which  can  be  bought  at  the  druggist's. 

If  it  is  possible  to  get  the  spoon  in  wliich  the  sugar  is  heated  suffi- 
ciently hot  to  burn  the  sugar  completely,  it  will  be  discovered  that 
there  remains  behind  a  small  portion  of  white  powder,  which  the  most 
intense  heat  does  not  consume.  This  is  the  mineral  matter  of  the 
milk.  It  constitutes  about  seven-tenths  of  1  per  cent  of  its  weight, 
and  it  is  more  abundant  in  comparison  with  other  nutrients  than  in 
au}^  other  common  food.  It  is  easy,  of  course,  to  see  why  this  mate- 
rial which  builds  the  bone  should  be  in  the  food  primarily  designed 
for  the  use  of  young  animals. 

Thus  by  simple  and  interesting  processes,  fat,  casein,  albumen, 
sugar,  and  minerals  may  be  separated  and  milk  may  be  shown  to  be 
a  mixture  of  many  valuable  solids  either  suspended  or  dissolved  in 
water.  Such  experimenting  shows,  too,  why  it  is  that  no  other  liquid 
is  regarded  as  a  true  substitute  for  milk  in  the  feeding  of  young  chil- 
dren. No  attempt  will  be  made  in  this  bulletin  to  give  exact  direc- 
tions for  the  modification  of  milk  for  feeding  babies,  because  this 
varies  with  individual  cases  and  is  a  matter  which  should  be  regu- 
lated by  the  physician  or  other  person  with  expert  knowledge.  Many 
valuable  books  give  such  directions  for  children  of  various  ages  and 
such  books  may  prove  very  helpful  to  the  mother  and  the  nuree.  A 
careful  consideration,  however,  of  the  facts  that  have  been  given  here 
about  the  different  solids  in  milk  should  make  it  possible  for  a  pei-son 
to  follow  tlie  directions  for  modifying  milk  more  intelligently  and  to 
understand  better  the  reasons  for  the  varying  proportions  given  in  the 
formulas  for  infant  feeding. 

ECONOMICAL  USE  OF  MILK. 

In  order  to  make  plain  what  is  meant  by  the  statement  which 
occurs  above,  that  it  is  very  often  economical  to  serve  milk  in  place 
of  other  foods,  but  extravagant  to  add  it  to  a  meal  which  from  the 
point  of  view  of  nourishment  is  already  adequate,  the  following  menu 
is  given,  wliich  may  be  called  a  "milkless"  bill  of  fare,  as  no  milk 
is  supplied,  except  in  so  far  as  it  enters  into  the  composition  of  the 
cake  or  other  dishes: 

Breakfast. — Oranges,  eggs  on  toast,  coffee  with  cream. 

Luncheon. — Cold  lamb,  potato  salad,  tea,  bread  and  butter,  preserves,  and 

plain  cake. 
Dinner. — Sirloin  steak,   potatoes,  asparagus,  bread  and  butter,  strawberry 

shortcake. 

The  nourishment  in  such  a  bill  of  fare,  which  has  been  selected  not 
because  it  is  any  more  desirable  than  a  thousand  others  which  might 
have  been  chosen,  but  merely  to  give  something  to  discuss,  would  of 
course  depend  on  the  size  of  the  portions  served.     For  the  purpose  of 

413 


CARE    OF    MILK   AND   ITS   USE   IN    THE    HOME.  15 

giving  some  idea  of  how  large  the  portions  should  be,  let  us  imagine 
that  the  family  being  served  consists  of  a  man,  a  woman,  a  boy  of  15, 
and  a  girl  of  12.  It  is  quite  generally  agreed  that  this  family  would 
usually  eat  and  would,  in  fact,  need  about  3.3  as  much  food  as  one 
man  would  need.  Without  going  into  all  the  figures,  it  may  be  con- 
sidered that  such  a  famil}^  would  get  enough  nourishment  from  the 
above  bill  of  fare,  if  the  amounts  of  foods  used  per  day  were  2  pounds 
of  meat,  Ih  pounds  of  flour,  |  pound  of  butter  (or  of  butter  and  other 
fats,  oil,  or  drippings),  1  pint  of  cream,  6  eggs,  |  pound  of  sugar,  4 
oranges,  2  pounds  of  potatoes,  1  bunch  of  asparagus,  1  box  of  berries, 
and  1  pint  of  canned  fruit.  These  materials  would  supply  the  re- 
quired fuel  and  would  give  11 J  ounces  of  proteids,  the  amount  usually 
considered  to  be  needed  each  day  by  the  family  of  the  size  given 
above.  The  cost  of  food  materials,  in  case  meat  is  20  cents  a  pound, 
butter  40  cents,  eggs  24  cents  a  dozen,  coffee  35  cents  a  pound,  cream 
20  cents  a  pint,  oranges  30  cents  a  dozen,  potatoes  $1  a  bushel,  aspara- 
gus 15  cents  a  bunch,  and  strawberries  15  cents  a  box,  would  be  not 
far  from  $1. CO. 

If  milk  were  taken  as  a  beverage  in  addition  to  the  other  mate- 
rials in  this  bill  of  fare,  every  quart  so  used  would  increase  the 
proteids  unnecessarily  by  more  than  an  ounce.  When  it  is  con- 
sidered that  the  entire  allowance  for  the  4  people  per  day  is  only 
11^  ounces,  it  will  be  seen  that  this  addition  is  quite  significant. 
The  addition  of  a  quart  of  milk  would  raise  the  cost  of  the  footl  by 
8  or  9  cents.  A  glass  of  milk  taken  as  a  beverage  at  each  meal  by 
eveiy  person,  amounting  to  3  quarts  per  day,  would  add  3^  ounces 
of  proteids  to  the  daily  diet  and  27  cents  to  the  cost  of  the  food 
materials  for  the  entire  family. 

But  if,  instead  of  adding  the  milk  to  the  other  foods,  it  were  substi- 
tuted for  some  of  them,  and  3  quarts  of  milk  were  purchased  instead 
of  half  a  pint  of  cream,  it  could  either  be  used  as  a  beverage  or  it  would 
supply  one-half  pint  of  cream  for  tea  and  coffee,  1  pint  of  half  milk 
and  half  cream  for  use  on  cereals  or  puddings,  and  2{  quarts  of 
skimmed  milk  for  cooking.  A  bill  of  fare  which  would  utilize  this 
milk  is  as  follows: 

BreaJ:fast. — Oranges,  oatmeal  with  half  milk  and  half  cream,  coffee  with  cream. 
Luncheon. — Egga  on  toast,  lettuce,  bread  and  butter,  tea,  old-fashioned  rice 

pudding  (1  quart  of  milk,  \  cup  sugar,  \  cup  of  rice,  flavoring). 
Dinner. — Cream  of  tomato  soup,  sirloin  steak,  creamed  25otatoes,  strawberry 

shortcake. 

So  far  as  the  nutritive  value  is  concerned,  the  milk  with  the  addi- 
tion of  the  small  amounts  of  oatmeal  and  the  rice  contained  in  tliis 
bill  of  fare  would  take  the  place  of  the  cream,  part  of  the  potatoes,  1 
pound  of  meat,  the  preserves,  and  the  cake  of  the  first  bill  of  fare. 
Using  the  same  sort  of  data  wdth  respect  to  food  prices,  the  computed 

413 


16  CARE    OF    MILK   AND    ITS   USE   IN    THE   HOME. 

cost  of  the  second  bill  of  fare  woiiKl  be  about  23  cents  less  than  that 
of  the  first. 

The  above  is  one  specific  example  taken  merely  for  purposes  of 
illustration  of  the  way  in  which  milk  may  be  substituted  for  other 
foods.  In  general,  in  making  this  substitution,  the  fact  given  on 
another  page  that  a  quart  of  milk  is  equal  in  nutritive  value  to  three- 
fourths  of  a  pound  of  beef  or  8  eggs  should  be  kept  in  mind.  Or,  to 
give  the  equivalent  in  smaller  amounts,  a  cup  of  milk  is  equal  to  3 
ounces  of  lean  beef  or  2  eggs  in  total  nourishment. 

FOOD  VALUE  OF  SKEVI  MILK. 

It  is  natural  to  ask  if  skim  milk  is  as  valuable  a  food  as  whole  milk. 
In  answering  this  question  several  points  must  be  taken  into  con- 
sideration, some  of  which  have  been  touched  upon  in  the  first  part 
of  the  bulletin.  Freshness  and  cleanliness  nmst  be  considered  as 
well  as  composition.  Milk  which  has  been  received  from  the  milk- 
man and  allowed  to  stand  long  enough  to  skim  should  probabh"  never 
be  given  to  children  under  2  years  of  age.  For  older  people  the  mere 
fact  of  its  being  old  need  not  be  taken  into  consideration.  If  skim 
milk  is  bought  as  such,  however,  it  should  alwa3's  be  thoroughly 
cooked,  unless  it  is  known  to  have  been  handled  carefully  and  to  be 
clean.  So  far  as  its  nutritive  value  is  concerned  it  has  a  trifle  more 
protein,  volume  for  volume,  than  whole  milk,  the  per  cent  being  3.4 
instead  of  3.3. 

Skim  milk  seems  to  some  people  rather  thin  for  use  as  a  beverage, 
but  others  value  it  for  this  very  quality.  If  it  is  allowed  to  stand 
until  it  sours  and  is  then  churned  or  beaten  until  the  curd  is  broken 
up  into  small  particles,  it  makes  a  familiar  and  wholesome  drink, 
often  used  under  the  name  of  buttermilk,  for  much  of  the  commercial 
buttermilk  is  thus  made  from  skim  milk,  some  cream  or  butter  fat 
being  sometimes  added.  For  cooking,  the  lack  of  fat  and  any  con- 
sequent lack  of  flavor  can  be  easily  made  up,  as  butter  or  less  expensive 
fats  can  be  used  with  it.  Pork  and  bacon  fat  make  a  particularly 
savory  addition. 

In  the  very  interesting  experiment  of  serving  penny  luncheons  to 
anemic  children  in  the  Boston  schools,  one  of  the  combinations  of 
food  that  it  was  found  possible  to  sell  for  the  low  price  of  1  cent  was 
skimmed  milk  and  bread  and  butter.  In  an  experiment,  made  in 
Birmingham,  England,  where  an  efl'ort  was  made  to  serve  food  eco- 
nomically to  underfed  children,  cocoa  made  with  skimmed  milk  was 
served. 

The  following  suggest  ways  in  v^liich  milk  may  be  used  in  the 
diet  applied  to  skim  as  well  as  whole  milk. 

413 


CARE   OF    MILK    AND   ITS   USE   IN    THE   HOME.  17 

MILK  SOUPS. 

A  large  variety  of  soups  may  be  made  the  means  of  utilizing  not 
only  milk,  but  also  left-over  portions  of  vegetables  and  other  foods. 
In  making  them  allow  from  one-half  to  1  level  tablespoonful  of  flour 
to  each  cup  of  liquid  (including  milk  and  the  juice  and  pulp  of  vege- 
tables) and  1  level  tablespoon  or  more  of  butter  or  other  fat.  Some 
of  the  flavorings  which  may  be  used  are:  Onions,  corn,  asparagus, 
cabbage,  cauliflower,  peas,  beans,  tomatoes,  salmon  or  other  fish, 
celery,  spinach,  or  grated  cheese. 

MILK  CHOWDER. 

Chowders  are  also  a  very  acceptable  means  of  serving  milk.  In 
making  rich  chowders  the  proportions  used  are :  Two  cups  of  milk  or 
of  milk  and  water,  1  cup  of  potatoes  cut  into  small  pieces,  and  1  pound 
of  fish.  The  flavoring  is  onions  and  fat  tried  from  salt  pork.  "VVliile 
these  proportions  make  a  rich  dish,  it  is  possible  to  reduce  the  amount 
of  fish  greatl}',  to  leave  it  out  entirely,  to  use  small  portions  of  left- 
over fish  or  some  salt  codfish  which  has  been  freshened,  or  to  substi- 
tute corn  for  it.  Such  dishes  are  palatable  and  of  reasonably  high 
nutritive  value  providing  the  greater  part  of  the  liquid  used  is  milk. 

MILK  GRAVIHe. 

A  great  variety  of  milk  gravies,  thickened  with  flour  and  enriched 
with  butter  or  other  fat,  may  be  served  with  potatoes  or  other  vege- 
tables or  poured  over  toast.  The  proportions  are  2  level  tablespoonfuls 
of  flour  and  2  level  tablespoonfuls  of  butter  to  1  cup  of  milk.  To  this 
may  be  added  chipped  beef,  codfish  or  other  fresh  or  salt  fish,  hard- 
boiled  eggs,  small  portions  of  chicken  or  veal  or  grated  cheese.  Milk 
gravy  flavored  with  cheese  makes  a  good  and  very  nutritious  sauce  to 
pour  over  cauliflower  and  cabbage  or  to  serve  with  boiled  rice  or 
hominy, 

A  very  good  way  to  serve  milk  toast  is  to  toast  bread  very 
thoroughly  and  to  pour  hot  milk  over  it  at  the  time  of  serving.  In 
serving  milk  toast  in  this  way  all  the  dishes  should  be  kept  very  hot. 
A  heavy  earthenware  pitcher  may  be  used  for  serving  the  hot  milk, 
as  it  retains  heat  for  a  long  time. 

Sour  milk  is  used  to  a  large  extent  in  cookery  and  the  sour  milk 
itself,  or  more  commonly  the  sour-milk  curd,  is  considered  by  many 
persons  a  palatable  and  wholesome  dish.  Sour  cream  is  also  used  in 
many  ways  in  the  household  in  the  malving  of  sauces  and  dressings 
and  in  cookery. 

413 


18  CAKE   OF   MILK   AND   ITS   USE   IN   THE   HOME. 

COTTAGE  CHEESE. 

Perhaps  the  most  common  name  in  the  United  States  for  the  freshly 
separated  skim-niilk  curd  is  cottage  cheese,  though  other  names,  for 
instance,  schniierkase,  are  also  well  known. 

Cottage  cheese  contains  all  the  proteids  of  milk  and  part  of  the  fat. 
It  is  made  either  by  heating  the  curd  slightly  and  straining  or  by  strain- 
ing it  without  heating.  If  any  heat  is  used,  it  should  be  very  gentle 
or  the  curd  will  become  hard  and  unpalatable.  A  safe  way  of  heat- 
ing is  to  pour  boiling  water  into  the  curd.  This  is  a  good  way  also 
for  those  wdio  do  not  care  for  the  taste  of  lactic  acid,  for  the  hot  water 
serv^es  to  remove  part  of  this. 

Cottage  cheese  would  probably  be  a  more  popular  dish  if  it  were 
served  in  a  greater  variety  of  ways.  For  many  palates  it  needs  to  be 
enriched  with  a  little  butter  or  cream.  The  French  variety,  to  which 
reference  was  made,  is  commonly  served  with  sugar  and  cream,  and 
a  similar  dish  is  eaten  in  the  United  States,  often  being  seasoned 
with  a  little  ground  cinnamon  or  nutmeg. 

Cottage  cheese  is  always  a  good  addition  to  or  accom])animent  of 
salads.  A  good  luncheon  which  can  be  served  in  one  course  consists 
of  cottage  cheese  in  which  the  first  portions  are  eaten  with  dressed 
lettuce  or  water  cress,  and  the  last  portion  with  a  little  of  some  rather 
sweet  fruit  preserve,  such  as  strawberry  or  raspberry  jam  or  pre- 
served quinces.  Served  with  bread  and  butter  and  tea  this  makes  a 
well-balanced  meal. 

Cottage  cheese  flavored  in  different  ways  may  be  used  for  sand- 
wiches. In  busy  households  it  may  be  well  to  prepare  the  filling  and 
to  allow  the  various  members  of  the  family  to  make  their  own  sand- 
wiches at  the  table.  Caraway  seeds,  chopped  stuffed  olives  of  dif- 
ferent sorts,  and  chives  (a  vegetable  which  may  be  easily  grown  in 
the  kitchen  window  as  well  as  the  kitchen  garden)  make  good  flavors. 
Instead  of  the  different  kinds  of  stuffed  olives,  plain  olives  and 
pimentos  may  be  chopped  separately  and  added,  but  this  requires 
more  work. 

The  question  is  likely  to  arise  why  sour  milk  and  its  products  are 
considered  safe  food  to  be  eaten  raw,  while  stale  sweet  milk  is  looked 
upon  with  some  suspicion  unless  it  has  been  cooked.  The  reason  is 
that  for  a  long  time  after  the  milk  is  drawn  all  the  bacteria  which 
enter  into  it  increase  in  number,  the  increase  being  more  or  less 
rapid,  depending  chiefly  on  the  temperature  at  which  the  milk  is 
kept.  Some  of  these  bacteria  may  be  kinds  that  produce  disease. 
Finally,  however,  when  milk  sours  the  harmless  lactic-acid  bacteria 
and  the  lactic  acid  which  they  produce  tend  to  destroy  other  micro- 

413 


CAKE    OF    MILK    AND    ITS    USE    IN    THE    HOME.  19 

organisms,  including  the  disease-producing  bacteria,  so  that  the  time 
comes  when  tlie  harmful  bacteria  decrease  very  rapidly  and  the  lactic- 
acid  bacteria  increase  very  rapidly.  By  the  time  the  milk  is  sour  it 
is  practically  free  from  bacteria,  except  those  of  the  lactic-acid  type. 

SWEET  CURDS. 

Sweet  curds  may  be  made  into  a  good  filling  for  pies  or  tarts. 
The  curd  is  obtained  by  adding  rennet  to  warm  milk  and  allowing 
the  milk  to  stand  until  it  hardens.  The  curd  is  then  broken  up  and 
strained.  To  the  curd  from  1  quart  of  milk  add  1  level  table- 
spoonful  of  butter,  one-quarter  of  a  cup  of  sugar,  the  yolks  of  2 
eggs,  and  a  few  Zante  currants  or  chopped  raisins,  and  a  little  nut- 
meg. In  earlier  times,  the  sweet  curd  from  cheese  mo  king  was  much 
used  as  a  food,  but  is  not  common  to-day,  though  sometimes  served 
where  it  can  be  readily  obtained  from  a  cheese  factory.  Wliey  was 
also  much  used  in  earlier  times  and  is  still  a  favorite  beverage  with 
many  and  employed  especially  in  invalid  dietetics. 

MILK  DESSERTS. 

Junket  served  very  cold  is  a  refreshing  dessert  in  hot  weather,  as 
are  the  numerous  milk  sherbets,  frozen  custards,  and  similar  desserts 
in  which  milk  is  used.  Baked  milk,  made  by  cooking  sweetened  and 
flavored  milk  for  a  long  time  in  a  slow  oven,  is  also  good.  Many 
different  kinds  of  puddings  are  made  by  baking  milk  with  cereals 
and  either  molasses  or  sugar.  The  cereal  may  be  rice,  corn  meal,  or 
buttered  white  or  v/hole-wheat  bread.  In  this  class  of  food  belongs, 
so  far  as  nourishment  is  concerned,  the  scalloped  potatoes  made  by 
cooking  sliced  raw  potatoes  for  a  long  time  in  a  large  amount  of  milk. 

BUTTERMILK. 

As  a  wholesome  and  nutritious  food  buttermilk  is  also  valuable. 
It  has  3  per  cent  of  proteids,  and  a  quart  contains  one-fourth  as 
much  proteid  as  a  man  needs  in  a  day,  even  if  the  most  liberal  esti- 
mate of  his  needs  is  taken.  It  is  said  to  possess  hygienic  value  as 
well,  the  theory  being  that  lactic-acid  bacteria  ma}^  grow  in  the  intes- 
tines, crowding  out  other  and  undesirable  kinds. 

Though  not  much  different  in  nutritive  value,  buttermilk  obtained 
as  a  by-product  in  butter  maldng  has  a  different  quality  or  texture 
and  a  different  flavor  from  so-called  skim-milk  buttermilk  referred 
to  above. 

413 


20  CARE   OF   MILK  AND   ITS   USE   IN'    THE   HOME. 

SUMMARY. 

Alilk   and  milk   products   are  wholesome   and   economical   foo< 
which  may  reatlih^  be  used  in  quantity  in  the  diet. 

Quality  and  cleanliness  in  handling  are   important   topics   whicj 
must  be  considered,  as  well  as  food  value. 

A  few  examples  have  been  given  of  the  use  of  milk,  skim  mill 
milk  curd,  and  buttermilk  in  the  home.     Others  will  readily  suggesj 
themselves  to  the  housewife. 


11 

ill 


[A  list  giving  the  titles  of  all  Farmers'  Bulletins  available  for  distribution  will  b« 

sent  free  upon  application  to  any  Member  of  Congress  or  the  Secretary  of  Agriculture. 

413 

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